1. Field of the Invention
The present invention relates to a control valve for an air cushion bed, and more particularly to a control valve having depressurization and air detection functions for an inflatable air cushion bed.
2. Description of the Prior Art
When a patient lies on the bed for a long period time, he/she may get bedsores caused by unrelieved pressure. An air cushion bed is used for patients so as to prevent a bedsore. This air cushion bed has air strips at the middle portion thereof for air inflation and air exhaust so as to lower the probability of bedsore. The relief of pressure is to avoid further sores.
As shown in FIG. 1, a conventional control valve 9 for an air cushion bed comprises an air intake pipe 91, an air bag 92, two push plates 93 and a three-way pipe 94. When the air enters the air bag 92 to inflate the air bag 92, the two push plates 93 will be moved to activate an inductive switch. Sometimes, the traditional air bag 92 cannot run exactly to influence the inductive result due to its material and configuration. Besides, the conventional control valve 9 has to cooperate with the three-way pipe 94. It is necessary to improve the entire effect and to lower the cost.
Accordingly, the inventor of the present invention has devoted himself based on his many years of practical experiences to solve these problems.